Blown Away: Supercharged KTM by Hazan Motorworks

Supercharged KTM custom motorcycle by Hazan Motorworks
The custom motorcycle world is moving fast. It’s a world of Photoshop renders, digital sketches, computer aided design and 3D printers. Which is good to see, but also makes us a little sad at times. Motorcycling is a visceral, mechanical experience, and injection molded plastics don’t quite have the charm of bodywork turned on an English wheel.

Fortunately, there are still a few guys who know how to operate a lathe and build a frame by hand. And Max Hazan is in the top echelon—because he adds artistic vision and historical appreciation to create an intoxicating mix.

Supercharged KTM custom motorcycle by Hazan Motorworks
Max is quite clear that this latest build isn’t designed for cross-country trips. “It’s just something that has two wheels and was fun to make,” he says. “There was no intention of making something practical.”

The idea for the KTM has been kicking around in Max’s head since he made his first bike in his dad’s workshop, while recuperating from an off-road accident.

Supercharged KTM custom motorcycle by Hazan Motorworks
“I made that bike for nothing, with virtually no metalworking tools. It had a Honda GX engine that cost $89 from eBay, plus some bicycle parts. The bike went way faster than I expected, and I knew that the next bike I built would have to be out of motorcycle parts.”

“So the idea here was to make something like the first motorized bicycle: light, cheap and fast,” says Max. “The KTM RFS [Racing Four Stroke] engine is perfect. It has the cleanest shape of the modern 450-type motors, it’s easy to work on, and it’s relatively bulletproof.”

Supercharged KTM custom motorcycle by Hazan Motorworks
A quick hunt on Craigslist turned up a clean KTM 520 with a full Öhlins setup. Max hauled out the engine, and put the other trick bits aside for his own SMR track bike.

To prevent things from getting too straightforward, he then plumbed in an AMR350 supercharger. It’s an obscure Roots-type blower made by Aisin, and similar to the tiny superchargers fitted to small, Japanese-market subcompacts. Still, the performance boost is nothing to be sniffed at: it displaces 300cc of induction air per revolution.

Supercharged KTM custom motorcycle by Hazan Motorworks
To hook up the blower, Max has machined a blower-drive/stator cover with a sealed drive shaft, and an aluminum blower ‘snout’—all from blocks of 6061 aluminum, turned by hand the traditional way on a Bridgeport mill. “After 30 hours of turning knobs, they were done.”

The bike is way more powerful than expected. “I ran the blower gearing at 1:1 to start, and found it perfect at about 7 to 8 psi. I actually left the engine compression stock: I just run the bike on 110 octane race fuel, and back off the ignition timing a few degrees at the crank trigger.”

Supercharged KTM custom motorcycle by Hazan Motorworks
The fuel mix is now fed through a single Keihin FCR41 carb—“With monster jets, the bike drinks fuel”—and the engine now makes around 85 hp at the crank. “It runs like a stock motor, but it’s just a little trickier to start. And it leaves you deaf after riding it!”

The radiators are oil coolers from a Cummins diesel, believe it or not, and coolant runs through part of the frame. (A separate part of the frame is used as a catch can for the engine breather.)

Supercharged KTM custom motorcycle by Hazan Motorworks
As you might expect, there’s no ABS, no CAN bus, and no ride-by-wire. So the electronics are very minimal, mounted under the engine next to a tiny 4-cell lithium battery. It’s good for about 30 seconds of cranking with no decompression.

The frame looks minimal, but Max reckons it’s the strongest one yet to roll out of the Hazan Motorworks shop. It’s all 1/8-inch wall, 1.25-inch chromoly tubing, with the neck milled from a solid block.

Supercharged KTM custom motorcycle by Hazan Motorworks
The forks and front suspension are equally unique, carved or machined from solid 2-inch chromoly bar stock. Although some of the parts are heavy, the finished bike clocks in at a mere 245 pounds wet—around 111 kilos.

Much of the effort on this build went into the unusual rear hub setup. “That was about a third of the cost of the whole project,” Max reveals. “It was an idea that I had, but required sending the design to a CNC shop.”

Supercharged KTM custom motorcycle by Hazan Motorworks
The hub uses an asymmetrical lacing pattern—radial 10-spoke on one side, crossed 20-spoke on the drive side), and does not have any hub flanges. The spokes lace through the sprocket itself—which is ½-inch 700 series aluminum.

The rear brake is another first. “I was initially going to run a rotor off the drive sprocket, which has been done many times before,” says Max. “But then ran into clearance issues with the supercharger drive. So I decided to run a shaft to the rotor, driven by another sprocket.”

Supercharged KTM custom motorcycle by Hazan Motorworks
When the first images of the KTM appeared on the net, some folks got all hot and bothered by the brake setup. “They were saying it wouldn’t work, it wouldn’t stop, the wheel would flex, and the chain would skip,” says Max.

“All understandable concerns while it was being designed, but it’s now been ridden and tested. It works just fine, and it doesn’t fade when hot.”

Supercharged KTM custom motorcycle by Hazan Motorworks
Bodywork? There’s very little of it, but it’s gorgeous. The slim tank is hand-fashioned from 6061 aluminum, and at the front (on the left side) is a separate coolant reservoir.

The finish is ‘Black Nickel,’ a first for Max. “It’s polished and plated in the traditional way, then chemically tinted, then clear coated. It looks amazing but it has to be treated like paint—it’s much more delicate than regular nickel plating.”

Supercharged KTM custom motorcycle by Hazan Motorworks
The wheels and ‘clincher’ tires are an age-old combination that Max is familiar with. Each rim has a flange that interlocks with the bead of the tire, in a system and size that owners of the Ford Model T and its contemporaries will recognize.

“I wouldn’t trust them to drag your knee,” says Max, “but I’ve never had an issue with those tires—as long as they are in decent shape, and fully inflated. They offer a hard ride when running at the required 55 to 60 psi. I have tried to run 30 psi and they just slide on the rim. Definitely not the most ‘performance’ tire out there.”

Supercharged KTM custom motorcycle by Hazan Motorworks
So what’s it like to ride? “Amazing and terrifying at the same time. There’s a foot clutch and a tank shift, and it’ll lift the front wheel in the first four gears. It’ll also take your shoelaces and pants if you don’t pay attention.”

“The KTM is not street legal,” says Max. “It is what it is—something I wanted to make for sake of making something. It goes and stops and puts a smile on my face.”

Supercharged KTM custom motorcycle by Hazan Motorworks
We must thank motorcycle enthusiast Robert (Bobby) Haas for making this build possible. He commissioned it for the Haas Motorcycle Gallery in Dallas—which displays vintage bikes dating back to the start of the twentieth century, and more modern customs such as Craig Rodsmith’s turbocharged Moto Guzzi.

“Robert is also the man that kept the doors open at Hazan Motorworks when I was literally one day away from going back to a full time job three years ago,” says Max.

So what’s next? “I’m currently working on another Royal Enfield ‘Musket’,” Max reveals. “I also have a 1938 JAP 500 on deck. After the commissioned bikes are done, I’ll do a personal build—a KTM 950 supermoto that I’ve been dreaming up for a little while.”

“Aircraft engines and a twin-turbo rotary will also have to happen at some point…”

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Supercharged KTM custom motorcycle by Hazan Motorworks